The objectives of this Center are to undertake systematic, interdisciplinary studies of the structure and function of the plasma lipoproteins, particularly their apoprotein moieties, to delineate in detail their function in the transport and metabolism of lipids, especially triglycerides and cholesterol, to determine the mechanisms and prevalence of specific hyperlipoproteinemic disorders and to evaluate methods for treating them. This supplemental request is to provide for expansion of two of our six projects and to strengthen our Core Facility. Expansion of research in lipid enzymology is proposed to apply immunological and isotopic tracer methods to investigate the pathways of formation of lipoprotein lipase at the endothelial surface of blood capillaries, to determine the site of its synthesis, the requirements for transfer of precursor to the endothelium and the influence of hormones on its synthesis and degradation. The nature of the endothelial lipoprotein lipase binding-site will be studied with the aid of antibody-Sepharose columns and new methods involving lipase antibody and lipase inhibitor will be applied to the study of the enzyme in post-heparin plasma of patients with various primary hyperlipemic disorders. Research on the treatment of familial hyperbetalipoproteinemia will be extended to the use of combinations of drugs and to higher dosage schedules. Studies of the primary structure of specific apolipoprotein subunits will be facilitated by improving the efficiency of automatic amino acid analysis. Collaborative studies with other laboratories will be expanded by providing for continuing participation of established investigators from other institutions in the various fundamental research programs for periods of one to twelve months.